Fuel feeding apparatus fob furnaces



y 1943- e. MOA. BLIQZAVRD. 2,320,062

FUEL FEEDING AI PARATUS FOR FURNACES Filed March 15, 1940 s Sheets-Sheet 1 INVENTOR GEORGEMcAvl'ntBuZARD ATTORNE s May 25, 1943. s. M A. BLIZARD FUEL FEEDING APPARATUS FOR FURNACES Filed Mafch 15 1940 3 Sheets-Sheet 2 M mm Bu 2 m wm Bi n6 a? I. Hw VQMMM I F W 4% G. M A. B LIZARD FUEL FEEDING APPARATUS FOR FURNACES FiledMarch 1:5,1940 s Sheets-Sheet 3 M (6f Ari znhrlzs n 0 T m. V N I GEORGE McAVI'I-YBUZARD Wm/a Patented May 25, 1943 FUEL FEEDING APPARATUS FOR FURNACES George McAvity Blizard, Saint John, New Brunswick, Canada Application March 15, 1940, Serial No. 324,182 In Canada February 7, 1940 4 Claims.

This invention relates to fuel feeding apparatus for furnaces, the object being to provide an improved apparatus of this type which is especially adapted for small domestic furnaces.

'An important feature of the invention resides in the provision of an electrically operated fuel feeding apparatus which, when connected in circuit with the same aquastat or thermostat which controls the blower of the furnace, provides a complete automatic stoker which operates to feed coal to the furnace whenever the blower is cut in by: the aquastat cr thermostat. 1. Another feature of the invention resides in th provision of fuel feeding apparatus which is simple in construction, efiicient in operation, and may be easily and quickly applied to feed fuel through the fire door opening of the furnace.

A further feature of the invention resides in mounting the fuel feeding'apparatus so that it may be easily and quickly detached from the furnace and displaced to an out-of-the-way position with reference to the fire door opening. This facilitates installation of a conventional fire door so that hand firing canb'e resorted to in case of accident or failure of the fuel feeding mechanism.

"Another advantage of the fuel feeding apparatus provided in accordance with this invention is that it can be used equally well for feeding anthracite buckwheat, soft coal slack, or a mixture of the two, and is designed so that it may be installed by one person in a few hours without changing the furnace grates or resorting to any changes in the furnace construction other than the removal of the conventional fire door.

Proceeding now to a more detailed description of the invention reference will be had to the accompanying drawings, wherein "Fig. 1 is a front view of a furnace equipped with my improved fuel feeding apparatus.

Fig. 2 is a View similar to Fig. 1, but showing the fuel feeding apparatus swung to an out-ofthe-way position with reference to the fire door opening of the furnace.

Fig. 3 is a perspective view, partly broken away, showing the interior construction of the fuel feed box forming part of the fuel feeding apparatus. Fig.4 is a view showing the plate of the fuel feeding apparatus which takes the place of the conventional fire door. This view also shows the arrangement of the deflectors provided for ensuring even distribution of the coal delivered to the furnace.

:- Fig. 5 isan enlarged front elevational view of.

the fuel feed control mechanism forming part of my invention.

Fig. 6 is a sectional view taken along the line 6-6 of Fig. 5.

Fig. 7 is a vertical sectional view of a combined mufiier and oil reservoir forming part of said invention.

Referring more particularly to the drawing 5 designates a domestic furnace and 6 the fuel feeding apparatus provided in accordance with my invention.

1 As here shown my improved'fuel feeding appa ratus comprises a plate 1 provided with a sleeve, 8 which is rotatably mounted on a hollow ver-' tical pipe 9 having its lower end screwed into and closed by a flange fitting 10 which is bolted to; the floor ll. Sleeve 8 is supported on pipe 9 by a collar I2 which is fastened to the pipe at a suit able elevation by means of the set screw l3. Plate 1 carries the fuel feed box 14 which is surmounted by the fuel feed hopper [5. The fuel falling from.- the hopper l5 passes into a chute l5 (Fig. "3). having its bottom wall formed in two sections designated I1 and 18. The lower part of section I! overlaps and is spaced from the upper part of section l8 (Fig. 3) to provide an intervening air passage IS. A fuel measuring or meter wheel 20 is mounted in the chute 16 above the air passage l9 and is driven in an anti-clockwise direction (as viewed in Fig. 3) by its supporting shaft 2| when the latter is driven from the motor 22 by the drive mechanism generally indicated at. 23 in Fig. 1. A nozzle head 24 is arranged in the fuel feed box l4 and is provided with three nozzle openings 25 through which three jets of air rep--.

resented by the arrows 26 in Fig. 4 are directed downwardly through the air passage 19 and overthe upper surface of the chute wall I8. The nozzle head 24 is connected by pipe 21 and tubing. 28 (Fig. 1) to the upper part of pipe 9 which serves as a compressed air storage tank to which compressed air is supplied through line 29 from the pressure side of a compressor 30 mounted on, the plate 1-. Compressor 30 is driven from motor 22 by the drive shaft 3| which also serves as the drive shaft for the fuel feed operating mechanism 23.

A door plate 33 is attached to the main supporting plate 1 by the spring connections 34.

shown in Fig. 2. When the fuel feed apparatus is swung to the operative position shown in Fig. 1, the fire door plate 33 is pressed tightly against the door frame 35 surrounding the fire door,

opening 36 of the furnace. Plate 33 is provided with. an opening 31 through which the fuelis delivered from the chute wall l8 to the interior of the furnace. Plate 33 is also provided with a fuel distributing platform 39 which extends inwardly through the fire door opening 36 and serves as a continuation of the chute wall 18. Platform 3.9 is bounded by side walls 40 and is equipped with deflectors 4|. The deflectors 4| serve to ensure even distribution of the fuel over the central and side portions of the furnace fire box.

The fuel feed operating mechanism generally indicated at 23 in Fig. 1 is shown more clearly in Figs. and 6. It includes a pair of pin carrying plates 45 and 46 fixed to rotate with the right hand end of motor driven shaft 3|. These plates carry the drive pins indicated at 41, 48 and 49. The smooth portion 41a of each pin extends slidably through an opening provided in one ofthe arms 45a of the plate 45. The threaded portion 41b of each pin is threaded through a screw threaded opening provided in one of the arms 46a of the plate 46, it being noted that the plates Hand 46 are of duplicate construction. Stop nuts 54 are fixed to the central portion of each of the pins 41, 48 and 49. These stop nuts enable the pins 41, 48 and 49 to be turned by a wrench when it is desired to shift the pins either to the left or to the right relative to the pin carrying plates 45 and 46. In. Fig. 5 I have shown the pin 41 shifted to the left relative to plates 45 and 46 so that the left hand end of this pin protrudes beyond the left hand side of plate 45 for engagement with the points 53 of a star wheel 54 fixed to the shaft 21 which carries the meter wheel 26. The remaining pins 48 and 49 areshown shifted to the right so that their left hand ends do not protrude suificiently beyond the plate 45 to engage the points of the star wheel 54.

With the pins 41, 46 and 49 arranged as shown in Figs. 5 and 6, it is obvious that, during each complete revolution of the motor driven shaft 3|, the pin 41 engages a point 53 of the star wheel 54 to effect a partial revolution of the meter Wheel shaft 2i. If it is desired that the meter wheel be given three impulses for each complete revolution of the shaft 3!, this may be accomplished by shifting pins 48 and 49 to the left so that their left hand ends will protrude sufficiently beyond the plate to engage the points 53 of the star wheel 54. It will also be evident that, with the shaft 35 turning continuously in an anti-clockwise direction as viewed in Fig. 6, the number and spacing of the impulses imparted to shaft 2i for each revolution of shaft 3! may be varied by appropriate adjustment of the pins 41, 48 and 46. For example, if the pin 48 is shifted sufficiently to the left to engage the star wheel, the interval between the impulses imparted to the star wheel by the pins 41 and 48 will be less than the interval betweenthe impulses that would be imparted to the star wheel if the pin 48 were left in its retracted position and the pin 49 shifted to the left to a projected position corresponding to the projected position of pin 41'.

The pins 41, 48 and 46 also serve to impart swinging movement to the arm 55 of a bell crank lever 56 which is pivoted to a suitable bracket 51. The remaining arm 56 of the bell crank lever is provided wtih a valve operating extension. 59 which is arranged to engage and open a normally closed valve 60 controlling the flow of air through a valve casing 6i forming part of the air line 21 leading to the nozzle head 24. With the pins 41, 48 and 49 arranged as shown in Figs. 5 and 6 it will. be apparent that, as the pin 41 moves against and operates the star wheel 54, it also operates the lever 56 to open the valve 60 so that the delivery of the air jets 26 through the nozzle head openings 25 is synchronized with the operation of the meter wheel 20.

That part of shaft 3| which is located at the right of the compressor 35 is divided into two sections which are geared together by suitable reduction gearing (not shown) contained in the gear casing 3 la.

The pressure maintained in the pipe or storage tank 9 is indicated by a pressure gauge 64 and is regulated by a pressure relief valve 65 which is preferably set to prevent the pressure in tank 9 exceeding 12 to 14 lbs. per square inch.

When the fuel feeding apparatus described herein is in operation a measured quantity of fuel is permitted to pass from the hopper I5 to the discharge end of the platform 39 each time the meter wheel 20 is operated by the drive mechanism 23. As will be evident from the previous description of mechanism 23, the valve 60 is opened at each operation of wheel 20 and jets of air are delivered through the nozzle head 24 to accelerate the downward movement of the fuel as the latter passes downwardly over the upper surface of the chute wall 28. As the fuel passes from the platform 39 it is evenly distributed over the center and sides of the fire box by the distributing action of the platform walls 40 and the deflectors 4|. The throw and spread of the fuel is governed by the pressure of the air jets delivered through the nozzle head 24, the pitch and curvature of the chute walls 11 and I8, and the arrangement of the deflectors 4i. These factors are correlated so that, for a given size of fire pot, an even spreading of the fuel is maintained while the fuel feeding apparatus is in operation.

In case of accident-or failure of the fuel feeding mechanism, the plate 1 and the parts carried thereby may be swung about the pipe or tank 9 to the inoperative position shown in Fig. 2. This makes it possible to apply a conventional fire door to the fire door opening 36 to provide for hand firing of the furnace. When the fuel feedin apparatus is swung to the operative position shownin Fig. it serves as a combined fire door and stoker.

The furnace 5 is shown equipped with an air pipe 66 through which air is blown into the ash pit by a conventional blower (not shown) which is automatically cut into and out of operation by a conventional aquastat switch 61. As indicated at 22a, the motor 22 may be connected in circuit with the switch 61 so that the fuel feeding mechanism is put into and out of operation simultaneously with the cutting in and out of the blower.

The inlet side of the compressor 36 is fitted with a combined muffler and oil' reservoir which is generally indicated at 16 in Fig. 1 and is shown in detail in Fig. 7. In the last mentioned figure the air inlet pipe 1| of the compressor is shown extending upwardly through the bottom wall of a tank 12 which is filled with oil to a level 13 which is slightly below the upper end of pipe 11. A funnel 14 is fitted on the upper end of pipe 1| and contains a filter element 15 which may be made of felt or other suitable material and which also serves as a silencer. Tank 12 is provided with an oil level gauge 16 and an air admissionopening 11, the latter being covered at the outer side of the tank by a screen 18 and at the inner side by a wick 19 which extends downwardly-to the bottom of the tank. The air sucked in through the opening 11 is saturated with oil-as it passes through the oil saturated wick I9 and is drawn into the compressor inlet pipe H through a filter 15.

Having thus described what I now consider to be the preferred embodiment of this invention it will be understood that various changes in the construction and arrangement of parts may be resorted to within the scope and spirit of the invention as defined by the appended claims.

Having thus described my invention, what I claim is:

1. Fuel feeding apparatus for furnaces comprising a supporting plate with an opening, a hopper, a downwardly inclined feed chute projecting through said opening through which fuel is conducted from the hopper to the furnace, a meter wheel shaft extending through the said chute at a point between the hopper and the delivery end of the chute, a meter wheel fixed to rotate with said shaft, a star wheel fixed to said shaft exteriorly of said chute, a bottom wall in said chute comprising a plurality of sections, one of said sections being curved to form a basin directly beneath said meter wheel and having its lower portion projecting downwardly in overlapping relation to the upper portion of a second section, said overlappping portions being spaced apart to provide an air inlet passage, a nozzle head arranged to deliver air into the feed chute through said air inlet passage, a supply pipe through which compressed air is delivered to said nozzle head, a valve normally closing said pipe, a drive shaft equipped with devices engageable with said star wheel to effect intermittent rotation of the meter wheel shaft, and means actuated by said devices for automatically opening said valve at each operation of said meter wheel shaft.

2. Fuel feeding apparatus for furnaces comprising a supporting plate with an opening, a fire door plate provided with an opening therein and attached to said supporting plate, said fire door plate adapted to be pressed tightly against the door frame surrounding the fire door opening of the furnace, a hopper, a downwardly inclined feed chute projecting through said supporting plate opening and aligned with said fire door plate opening, said chute adapted to feed fuel from the hopper to the furnace, a meter wheel shaft extending through said chute at a point between the hopper and the delivery end of the chute, a meter wheel fixed to rotate with said shaft, a star wheel fixed to said shaft exteriorly of said chute, a bottom wall in said chute comprising a plurality of sections, one of said sections having its lower portion projecting downwardly in overlapping relation to the upper portion of a second section, said overlapping portions being spaced apart to provide a downwardly inclined air inlet passage, a nozzle head arranged to deliver air into the feed chute through said air inlet passage, a supply pipe through which compressed air is delivered to said nozzle head, a valve normally closing said pipe, a drive shaft equipped with devices engageable with said star wheel to effect intermittent rotation of the meter wheel shaft, and means actuated by said devices for automatically opening said valve at each operation of said meter wheel shaft.

3. Fuel feeding apparatus for furnaces comprising a feed chute, means for supplying fuel to one end of said chute, a meter wheel shaft extending through the chute intermediate the ends of the chute, a meter wheel fixed to rotate with said shaft and positioned within said chute, a nozzle through which air is supplied to said chute between the meter wheel and the remaining or discharge end of the chute, said nozzle being arranged to direct the air toward the discharge end of the chute, a normally closed valve controlling the flow of air to said nozzle, a star wheel fixed to said shaft exteriorly of said chute, a drive shaft equipped with devices engageable with said star wheel to effect intermittent rotation of the meter wheel shaft in a fuel feeding direction and means actuated by said devices for automatically opening said valve at each operation of said meter wheel shaft, said last mentioned means comprising a pivotally mounted lever having one end disposed to be engaged by said device during rotation of the drive shaft and the other end disposed to engage said valve for automatically opening said valve at each operation of said meter wheel shaft.

4. Fuel feeding apparatus for furnaces comprising a feed chute, means for supplying fuel to one end of said chute, a meter wheel shaft extending through the chute intermediate the ends of the chute, a meter wheel fixed to rotate with said shaft and positioned within said chute, a nozzle through which air is supplied to said chute between the meter wheel and the remaining or discharge end of the chute, said nozzle being arranged to direct the air toward the discharge end of the chute, a normally closed valve controlling the fiow of air to said nozzle, a star wheel fixed to said shaft exteriorly of said chute,

a drive shaft, a pair of pin carrying plates fixed to rotate with said drive shaft, a plurality of driving pins carried by said plates and adapted to be moved relative to said plates into and out of engageable relation with the star wheel, and a pivotally mounted lever having one end disposed to be engaged by said driving pins during rotation of the drive shaft when said pins are in engageable relation with the star wheel, the other efid of said lever being disposed to engage the valve for automatically opening same at each operation of the meter wheel shaft.

GEORGE McAVI'I'Y BLIZARD. 

